Light-projecting apparatus.



R. E. JONES.

LIGHT PROJECTING APPARATUS.

APPLICATION FILED DEC-22, 1916.

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LIGHT PROJECTING APPARATUS.

APPLICATION FILED 0Ec.22. 1915.

1 35,484. Patented July 31, 1917.

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nulusn. JONES, or MILWAUKEE, WISCONSIN.

LIGHT-PROJEGTING APPARATUS.

Specification of Letters Patent. Patented July 31, 1917.

Application filed December 22, 1916. Serial No. 138,441.

apparatuses, and more particularly to a.

light projecting apparatus for use in connection with moving picturemachines and the like.

One of the main objects of the invention is to provide an apparatus ofthe character stated which is well suited for using the ordinarytungsten high power electric light in place of the] are light nowcommonly used, thus effecting a material saving in current andeliminating the great heat incident to the use of an arc. A furtherobject is to provide a projecting apparatus having means whereby thelight rays may be collected and concentrated within a relatively smallarea being uniformly'distributed over this area. A further object is toprovide a projecting apparatus having a tion,

fixed parabolic reflector and an adjustable concave reflector whichreceives the light rays reflected from the parabolic reflector,

a light opening at its apex and the concave reflector so shapedas toconcentrate light rays and direct them through this opening. A stillfurther object is to provide means for adjusting the concave reflectorand the lamp whereby accurate concentration of the light rays may beobtained. Another object is to provide a lens supporting means having apluralitv of spaced lenses removably mounted therein and means foradjusting these lenses toward and from each other. A still furtherobject is to provide a plurality of lenses so relatively shaped anddisposed as to first concentrate and then evenly distribute the lightrays over a relatively small area. Further objects will appear from thedetail description.

' In the drawings ,Figure l is a central vertical sectional viewtakenthrough a projecting apparatus constructed'in accordance with my inven-Flg. 2 is'a vertical section'taken through the lens supporting means,

Fig. 3 is a top plan view of'the lens supporting means.

The casing of the projector is formed with a cylindrical body or ring 1having a plurality of perforations 2 for ventilation purposes. This ringis provided at its rear edge with a peripheral flange 3. A concaved backplate 4 is secured to the back of ring 3 by means of screws 5 passedthrough the same and threaded into suitable bores in flange 3. To effecta light tight closure between this plate and the ring 1, the plate isprovided with a peripheral rabbet or recess which receives the edge ofthe ring, as shown in Fig. '1 of the drawings. A concaved reflector 6 ismounted within the casing in front of the back plate 4. This reflectormay have a reflecting surface formed from highly polished silver plate,or a glass mirror of usual construction may be utilized, if desired. Inthe construction shown the inner face of the reflector 6 is given a veryhigh polish to form the reflecting surface. Reflector 6 is provided witha central rearwardly extending boss 7. This boss has an approximatelyhemispherical. socket 8 which receives the inner half of a bearing ball9 the outer portion of which is mounted in a similar socket 10 formed inthe inner end of a sleeve 11 threaded through a boss 12 formed on theouter face of back plate 4, at the center thereof. The reflector 6isprovided with a central bore 13 which communicates with the socket 8and is in axial alinement with a smaller diametrical bore 14 extendingthrough the ball 9. The

reflector 6'is further provided, on its outer face, with a plurality ofbosses in each of which is secured a threaded screw stem 15.

In practice I prefer to use three or. more of these screw stemspositioned concentric with bore 13 and spaced equidistant, when threestems are used being spaced" 120 apart. These stems extend through bores16 through the back plate 4, these bores being of somewhat greaterdiameter than the screw stems. A thumb nut 17 is threaded on theouterportion of each screw stem'and bears against a boss 18 integral with theback plate. By means of the thumb nuts-17 and screw stems 15, thereflector 6 may be adjusted or rocked about the ball 9 so as to vary itsangle slightly relative to the axis of the casing thus permittingaccurate adjustment of the reflector so as to concentrate thegreatestpossible number of light rays at the desired point. Also, bythreading the sleeve 11 into or out. of the boss 12, and threading thumbnuts 17 onto or off of the screw stems 15, the .reflector 6 may beadjusted axially with the same object in view.

A cover plate 19 is secured to the front flange 20 of ring 1. This coverplate is of approximately parabolic shape,- the inner face thereof beinghighly polished to'produce a parabolic reflector 21. This cover plate isprovided with an integral inwardly extending peripheral shoulder 22,.and a peripheral securing flange '23 through which are inserted thesecuring screws 24. The shoulder 22 serves to effect a light tightclosure between the ring 1 and the cover plate and also serves to securethe parabolic reflector 21 in accurate adjustment in the casing.

'The cover plate 19 is provided, at its apex, with a circular lightopening 25. An integral boss 26 is formed on the outer face of .the.cover plate concentric with the light opening 25. A U-shaped lenssupporting .frame27 is secured to this boss by means of. securing screws28 inserted through lugs 29 formed at the inner end of the frame andthreaded into suitable bores in boss 26. This rected longitudinallyextending flange 32 formed at the upper edge of each arm of frame 27integralthrewith' Flange 32 is provided with a longitudinally extendingslot 33. This slot receives an adjusting screw which is passed throughthe same, a securing nut 35 being threaded on the screw beneath theflange. Screw 34 is provided with j a button head 36 which fits snuglywithin a bore 37 extending throu h the horizontal flange of car 31.. Bythis means, the lens holding plate 30 is demountably secured in the lensframe 27 and may be quickly and easily removed, when necessary, bylifting the plate sufficiently to disengage the cars 31 from the heads36 of the screws 34. The

screws 34 and nuts 35 threaded thereon pro vide means for gripping theflan es 32 of frame 27 whereby the lens' holding plate may be quicklyand easily adjusted longitudinally of the frame.

Plate 30 is mounted in the frame 27 in'the i same manner as plate 30.Plate 30.is provided, at its center, with a circular'opening 38 and aninwardly extending lens holding -51 is secured to the plate adjacent thelower end thereof concentric with the lens openmg 50. This strip has anupwardly and outwardly d1rected lens holding flange 52 which extends infront of the lowerportion of the lens opening. This strip receives thelower peripheral portion of an outwardly directed concavo-convex lens 53mounted in front of the lens opening 50, this lens being secured inposition by a clip 54 secured at the top of plate 30 at the centerthereof, having an angularly disposed flange 55 adapted to engage overthe edge of the lens. By this means the lens 53 is secured tightly onthe lens holding plate30 in proper position and may be quickly andeasily demounted or removed from this plate when desired. A lens holdingplate 56. is mounted in the frame 27 adjacent the outer end thereofsimilarly to the mounting of plate 30. Plate 56 is provided with a lensopening 57 over which is secured an inwardly directed Plano-convex lens58 detachably secured on the plate by the securing strip 59 and clip 60.A sheet metal cover 61 is hingedly secured to cover plate 19 above theboss 26, as at 62. This cover is of rectangular cross section and isadapted, when in lowered position, to fit snugly over the top of lensframe 27 so as to effect a light tight closure therewith. Each sideflange 61 is cut out at its inner end, as at 63, so as to accommodatethe securing lugs 29' formed at the inner ends of the flanges 32 of theframe. By raising this cover easy access to the lenses for adjustment,cleaning, or replacing, is obtained.

A lamp-socket tube 63 is inserted throughthe bore 14 of ball 9. Thistube extends in ward somewhat beyond the inner face of deflector 6and-is provided, on its inner end, with an electric lamp socket 64. Anelectric lamp 65 is mounted in the socket 64 and provides the source oflight for the apparatus. This lamp may be of any suitable type but is,preferably, a tungsten filament lamp the bulb being filled with nitrogento produce an-intense light. A thimble 66 of insulatingmaterial issecured on the outer end of the tube 63, which extends through andbeyond sleeve 11. This 'thimble surrounds the cord or cable '67 by meansof which the socket 64 is connected to the opposite sides of anysuitable source of electrical energy. The tube 63 is of considerablyless diameter than sleeve 11, and is secured in the sleeve by means ofset screws 68 threaded through the sleeve and engaging the tube. Anysuitable number of these set screws may be used, but in practice Iprefer to use three set screws spaced 120 apart about the sleeve. Setscrews 68 serve to hold the tube 62 in axial adjustment and. may also beused to rock the tube so as to adjust it an angle to the axis of thecasing, and consequently .the lamp 65, this rocking adjustment beingpermitted by the ball'9 through which tube 63 is inserted. By thismeans, the angle of adjustment of the lamp 65, as Well as its distanceaway from the reflector 6, may be quickly and easily adjusted or varied.so as to concentrate and direct the greatest number of light raysthrough the light opening 25. This adjustment of the lamp, inconjunction with the adjustment of the reflector 6 previously described,renders it possible to quickly and easily adjust the apparatus so as toinsure accuracy of operation and a maximum of efficiency.

The parabolic reflector 21 acts to direct the light rays from lamp 65rearward on to the concave reflector 6, these rays being die rectedalong paths parallel with the axis of the casing. The reflector 6 is soshaped that these light rays, which are parallel with the axis of thecasing, are reflected at such an angle as to be directed through thelight opening 25. The light rays Which arethus concentrated and flowthrough the opening 25 fall upon the inner face of the double concavelens l0. This lens, which is a divergent lens,

' acts to spread these light rays which then fall upon the innerconcaved face of the concavo-convex lens 53. the light rays to assumepaths approximately parallel with the axis of the lens. The light raysthen fall upon the convex face of the PlZIlO-COIlVQX lens 58. This lensacts to turn or deflectthe light rays slightly inward, thus causingconvergence of-the light rays and serving to concentrate the same withina relatively small area. By first spreading the light rays in the mannerdescribed, by meansof the lens 40, then collecting them by means of lens53, and concentrating them by means of the lens 58, a uniformdistribution of light .is obtained which is well adapted for use inconnection with moving picture machines and similar apparatuses.

The ring 1 is provided, at its under side, with an integral block 69.This block is provided with threaded bores 70 to receive securing screwsfor securing the apparatus to the slide of a table used in conjunctionwith a moving picture machine, in the usual manner. By-this means, theprojecting apparatus may be moved toward or away from the picturemachine. as circumstances may demand. 7

What I claim is:-

1. In light projecting apparatuses, a casing, a forwardly directedaxially-adjustable concaved reflector mounted in said casing, aninwardly directed parabolic reflector mounted at the front of thecasing, a lamp The lens 53 causes 2. In light projecting apparatuses, acylindrical casing, a concaved axially adjustable reflector mounted insaid casing,an inwardly directed arabolic reflector mounted at the frontof t e casing, a lamp intermediate said reflectors, and means exteriorof the casing for adjusting the lamp axially.

3. In light projecting apparatuses, a casing, a forwardly directedconcaved axially adjustable reflector rockably mounted in said casing,means exterior of the casing for adjusting said reflector axially andfor securing it in rocked adjustment, an inwardly directed parabolicreflector mounted at the front of the casing and having a light openingat its apex, light concentrating means mounted on said reflector inalinement with said opening, and a lamp intermediate said reflectors.

4:. In light projecting apparatuses, a casing, an inwardly directedparabolic reflector carried by said casing and having a light opening atits apex, a forwardly directed concaved reflector 'of uniform curvaturemounted within the casing for angular adjustment relative to the axis ofsaidcasing, a light intermediatesaid reflectors, and a common means forsupporting said concaved reflector and said light so as to permitindependent angular adjustment thereof relative to the axis of thecasing.

5. In light projecting apparatuses, a casing, a forwardly directedconcaved reflector rockably ,mounted in said. casing, a cover platesecured on said casing having its inner surface shaped to provide aparabolic reflecting means, said cover plate being provided with a lightopening at its apex, and a lamp intermediate said reflectors.

. 6. In light projecting apparatuses, a cylindrical casing provided witha detachable back plate, a forwardly directed concaved reflector mountedin said casing provided with a central rearwardly extending boss, saidboss having an approximately hemispherical socket and a centralbore, asleeve threaded through the back plate of the easing at the centerthereof and provided in its inner end with an approximatelyhemispherical socket, a bearing ball mounted in the sockets of said bossand sleeve and provided with a diametrical bore of less diameter thanthe bore through said boss, a tube inserted through said boss and sleeveand fitting casing for adjusting said reflector axially about said ball,an inwardly directed parabolic reflector secured to the front of saidcasing and provided at its apex with a light opening, and lightconcentrating means mounted on the parabolic reflector in aline mentwith the sald opening.

7. In light projecting apparatuses, a casing, a forwardly directedconcaved reflector mounted in said casing, an inwardly directedparabolic reflector mounted in front of the casing and having a lightopening at its apex, a double concaved lens mounted in front of saidlight opening, an outwardly directed concavo-convex lens mounted in adVance thereof, and an inwardly directed plano-convex lens mounted infront of said concavo-convex lens, all of said lenses being mounted inaXial alinement with each other and with said light opening.

8. In light projecting apparatuses, lens supporting means comprising asupporting frame of substantially U-shape in transverse cross sectionprovided with a longitudinally extending outwardly directed flange atthe upper edge of each'arm, each of said flanges being longitudinallyslotted, a lens holding plate mounted in said frame and provided withrectangular ears adapted to fit snugly over and about said flanges ofthe frame, each of said ears being provided with a bore in alinementwith the slot of said flange, a headed securing screw inserted throughsaid ear and flange, and a nut threaded on said screw beneath theflange, the head of said screw being of such size as to fit snugly intothe bore of said ear whereby the lens holding plate is removably held inthe frame and may be adjusted longitudinally of the same.

9. In lens holding means, a plate having a lens. opening, a lenssecuring strip car- RUFUS E. JONES. Vitnesses:

WV. A. HAYWARD, HUBERT STAHNKE.

